Recitation 3: Sensors – By Skyler Liu

Sensor: Ultrasonic Ranger (as a Distance Sensor)

Components:

1 * Arduino Uno

1 * USB-B to USB-A cable

1 * HC-SR04 Ultrasonic Sensor

3 * LED

3* 220-ohm resistors

Several jumper cables

Diagram:

Picture:

Videos:

Process: My partner chose an Ultrasonic Rager for our team. First, we tried to figure out how the sensor works. After we connected the circuit, we used the example code Ping to test the sensor. However, though we got some changes in the value on the monitor when we moved our hands in front of the sensor, we found the range of the value could even reach 3000 cm, which was obviously not correct. Then we got help from the assistant, she pointed out that the value was wrong because we didn’t connect both Trig and Echo to the same Digital Pin in the Arduino. After we corrected this mistake, the sensor finally worked normally. Then we started to add other components into the circuit. We first added one LED into the circuit and I suggested that we could take the example of the code we learned in the last course which was to command the LED to light up when the sensor value got below or beyond a certain number. After a few minutes trying, we successfully fit the piece of code into the Ping code and made the LED light up when the distance of something and the sensor was less than 20 cm. Then we tried to complicate the circuit and the code. We added another two LEDs into the circuit and altered the code. Finally, we made a device which would light up the green light when something is less than 50 cm from it; light up the orange light when something is less than 30 cm from it, at the end light up the red light when something is less than 10 cm from it.

Question 1:

What did you intend to assemble in the recitation exercise? If your sensor/actuator combination were to be used for pragmatic purposes, who would use it, why would they use it, and how could it be used?

We intended to assemble a distance annunciator which gives warning information by lights in the recitation. I think every resident could use the device. They can either assemble it in the doorway or put it in the car. It could warn the homeowner or the car owner if someone wants to stalk closer and intend to do a crime. We can also add rings into the device to make the warning more obvious.

Question 2:

Code is often compared to following a recipe or tutorial.  Why do you think that is?

I think the first reason is that they all need to run certain steps one by one. When we follow a recipe or tutorial, we need to do what it requires to do and cannot mix up the order, otherwise, the product might be horrible. Code is also like this. If the order of some commands is wrong, we would be very likely to not get the result as expected. Also, I think they are all the basis for work in each of their fields. For a new cook, a recipe is the basis for him to produce a meal and for the circuit, code is the basis for us to command the circuit to follow our ideas.

Question 3:

In Language of New Media, Manovich describes the influence of computers on new media. In what ways do you believe the computer influences our human behaviors?

I think the computer will make the public’s patience for obtaining information and publishing opinions decreased  – people will not wait for TV or broadcasts and other media due to the convenience and efficiency of getting information and making comments in the computer. Also, I think there will be fewer and fewer people going to the physical store because buying things through the computer is much easier, and online shopping is becoming safer and safer following the development of other technologies. There will be fewer reasons for people to not choose it.

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